PHP - CONSULTA ANIDADA

$insertSQL = sprintf("INSERT INTO productos_vendidos( id_producto,quantity, id_venta)

  SELECT cart_items.product_id, cart_items.quantity, productos_vendidos.id_venta

  FROM cart_items

  LEFT JOIN  productos_vendidos ON cart_items.product_id = productos_vendidos.id_producto

  where productos_vendidos.id_venta =

 (SELECT ventas.id

  FROM ventas

  LEFT JOIN productos_vendidos ON ventas.id= productos_vendidos.id_ventas ORDER BY id DESC LIMIT 1 ) ",

ventas (

  `id` bigint(20) unsigned NOT NULL auto_increment,

  `fecha` timestamp NOT NULL default '0000-00-00 00:00:00',

  `total_t` double NOT NULL default '0',

  `CEDULA` int(10) unsigned NOT NULL default '0',

  `NOMBRE_CLIENTE` varchar(30) NOT NULL default '',

  PRIMARY KEY  (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

productos_vendidos` (

  `id` bigint(20) unsigned NOT NULL auto_increment,

  `id_producto` bigint(20) unsigned NOT NULL,

  `quantity` bigint(20) unsigned NOT NULL default '0',

  `id_venta` bigint(20) unsigned NOT NULL default '0',

  PRIMARY KEY  (`id`),

  KEY `Index_2` (`id_venta`),

  CONSTRAINT `FK_productos_vendidos_1` FOREIGN KEY (`id`) REFERENCES `ventas` (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CONSTRAINT `FK_productos_vendidos_1` FOREIGN KEY (`id`) REFERENCES `ventas` (`id`)

CONSTRAINT `FK_productos_vendidos_1` FOREIGN KEY (`id_venta`) REFERENCES `ventas` (`id`)